<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /* 去除掉标签默认的margin和padding */
    * {
      margin: 0;
      padding: 0;
    }
    
    .box {
      width: 1226px;
      height: 614px;
      /* background-color: pink; */
      margin: 100px auto;
    }

    .left {
      float: left;
      width: 234px;
      height: 614px;
      background-color: #800080;
    }

    .right {
      float: right;
      width: 978px;
      height: 614px;
      /* background-color: yellow; */
    }

    .item {
      float: left;
      width: 234px;
      height: 300px;
      background-color: #87ceeb;
      margin-right: 14px;
      margin-bottom: 14px;
    }

    /* 找到的是 第 4 和第 8个 4倍数  4n */
    .item:nth-child(4n) {
      /* background-color: red; */
      margin-right: 0;
    }

    /* 找到从第5个开始往后的所有个子元素 */
    .item:nth-child(n+5) {
      margin-bottom: 0;
    }
  </style>
</head>
<body>
  <!-- 布局流程：从上往下，从外往内 -->
  <div class="box">
    <div class="left"></div>
    <div class="right">
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
    </div>
  </div>
</body>
</html>